Nov
14
2020

Why We See More Food Allergies

A recent review in a BBC article explained why we see more food allergies. It is important to note that one of the more important food allergies are peanut allergies. Certainly, they have risen from 1 in 250 children in 1997 to 1 in 70 children in 2008.

By all means, allergies come in various degrees of severity; an anaphylactic reaction is the most severe form. Notably, in England there was a rise of hospital admissions for anaphylaxis from 1,015 in 2013 to 1746 in 2019. This is a 72% increase in 6 years!

Theories why there may be more food allergies now

There are a number of theories why food allergies have been on the rise. There is a consensus now that the right composition of the gut bacteria is important for normal immune reactions to take place.

Hygiene theory

David Strachan proposed the hygiene theory of allergies in 1989. Briefly, his observation was that children of larger families were less likely to develop allergies. He interpreted this to mean that infections among siblings stabilized the immune system. In the meantime, it has become obvious that the gut plays an important role for the immune system.

Graham Rook’s “old friends” theory

Graham Rook’s “old friends” theory came out in 2003. This theory states that friendly microbes in the environment are mixing with the gut flora. This trains the immune system to balance.

Gut bacteria theory

There is good evidence that the more a child is given antibiotics as a child, the more likely it is that the person develops a food allergy later. The mechanism seems to go via the gut flora. In a way this is the other coin of Graham Rook’s “old friends” theory. If you kill the “good friends” bacteria in the gut by antibiotics, the immune system strikes back with allergic reactions.

Dual-allergen exposure

By exposing the child at 4 to 11 months to peanuts or peanut butter, the immune system develops tolerance to the peanut protein (LEAP=learning early about peanut). A study showed that by doing this 80% of 5-year and older children and adults do not have a peanut allergy.

Prenatal vitamin D and food allergies

A German study found that prenatal exposure to higher amounts of vitamin D resulted in a higher risk of developing food allergies before the age of two.

Use antibiotics only when necessary

Gut biome studies showed that the use of antibiotics can have long lasting effects on the composition of the gut flora. A patient in sepsis may require antibiotics. But when the patient has recovered it is important that the bowel flora is restored with probiotics. This balances the immune system and avoids allergic reactions.

Immunotherapy for food allergies

Allergists have long used desensitisation techniques to deal with inhalant allergies. Allergy shots every two or three weeks can be very helpful to suppress immune reactions to inhalants. The same technique works also for many food allergies. The allergist tests the patient’s skin on the forearm to see what positive reactions occur. Based on these findings an allergy serum is composed. A small amount is injected in intervals. The smallest amount is given first and the concentration is gradually increased until the maintenance dose is reached. This causes the immune system to produce competing antibodies that reduce the antibody-mediated reaction to the food allergies.

Why We See More Food Allergies

Why We See More Food Allergies

Conclusion

Food allergies are increasing in frequency and severity. There are several theories why food allergies develop. The most likely one is that friendly bacteria in the environment become part of the gut environment in the newborn. If we have the right composition of gut bacteria our immune system reacts normally. Administering antibiotics frequently and overcleaning our kitchens with too many cleaning agents affects our bowel flora negatively. This disbalance can cause allergic reactions. On the other hand, exposing a newborn between the age of 4 and 11 months to a variety of adult foods including peanut products will desensitize the child to peanut protein and prevent future allergies. Those who are severely affected by food allergies can see an allergist for allergy testing and consider desensitisation through allergy injections.

Jan
18
2020

Antibiotics In Children Can Trigger Allergies And Asthma Later In Life

Whoever treats a child’s cold must know that antibiotics in children can trigger allergies and asthma later in life. This is what a study released on Dec. 20, 2019 has shown. The researchers examined records of 798,426 children seen at the Department of Defense TRICARE health care program. They were born between 2001 and 2013. The physicians examined the children later again for allergies. The more antibiotics the children received in childhood, the more severe the youngster’s allergies were later in life.

More details about the study

The researchers found that different antibiotic types had different risks to cause allergic reactions later in life.

  • Penicillin: 1.3-fold risk
  • Penicillin with a β-lactamase inhibitor: 1.21-fold risk
  • Macrolides: 1.28-fold risk)
  • Cephalosporins: 1.19-fold risk
  • Sulfonamides: 1.06-fold risk

The type of allergies that the children developed later in life were food allergies, anaphylaxis, asthma, atopic dermatitis, allergic rhinitis, allergic conjunctivitis or contact dermatitis. The researchers stressed that their finding indicated an association between taking antibiotics and developing allergies later. It was not a causal relationship.

Food allergies in more detail

Anaphylaxis

This allergic condition is an emergency and requires immediate medical attention. It can occur when the body overreacts to peanuts or penicillin. It can occur with foods, and the reaction is sudden and severe. The symptoms may include wheezing, shortness of breath, a cough or tightness in the throat. The blood pressure may drop leading to light-headedness and passing out. The skin may show hives, swelling and a rash. The digestive symptoms may be nausea, vomiting and diarrhea. Other symptoms may involve itching eyes, headaches, anxiety and a feeling of impending doom.

Asthma

Airborne grass and tree pollens, mold spores and dust, but also peanuts and other strong allergens can trigger an asthma attack. The symptoms can be shortness of breath, wheezing, tightness in the chest, trouble falling asleep because of coughing and being short of breath.

Atopic dermatitis (eczema)

Often atopic dermatitis starts below the age of 5 and can last until late adolescence or adulthood. The symptoms can be dry skin, itching red patches of skin and thickened scaly skin. Allergic contact dermatitis is common in patients with atopic dermatitis.

Allergic rhinitis

People who suffer from allergic rhinitis are sensitized to particles in the air like grass and tree pollen, molds or cigarette fumes. They develop a stuffy nose, itching and watery eyes, sneezing and swelling around the eye lids. An allergist can do skin scratch tests to find out what the patient is allergic to. Subsequently, if the allergies are strong, the allergist may decide to start desensitization with allergy shots.

Allergic conjunctivitis

A person who is allergic to pollen and mold spores will react to this when in contact with it and often develop allergic conjunctivitis. An eye inflammation will develop within a few minutes leading to swelling of the conjunctiva around the eye ball. The eyes end up looking red, itching, burning and being watery.

Contact dermatitis

Contact dermatitis develops when your body brushes against a substance that your body has been previously sensitized to. One example is poison ivy contact dermatitis. But many other substances can cause similar reactions: solvents, shampoos, permanent wave solutions and rubbing alcohol. In addition, plants, bleach and detergents, fertilizers, pesticides and airborne substances (sawdust, dust from woollen materials) can also do the same.

The gut biome

Dr. Purvi Parikh is an allergist and immunologist at NYU Langone Health in New York. She was not involved in the study, but commented to it as follows: “One reason why there might be an association is because our microbiome, specifically in our gut, plays a large role in our immune systems. Antibiotics are known to not only kill the bacteria that are causing an infection, but also ‘good’ bacteria our immune system needs to protect us from developing allergic or autoimmune diseases.”

Treat bacterial infections with antibiotics when needed

She went on to say: “Overall, parents should know that this study shows an association but not necessarily cause and effect. So, if a child truly needs an antibiotic for a bacterial infection, they should not withhold it due to fear of allergic disease. However, on that same note, one should not over use antibiotics if not needed – for a virus or a cold – as there may be long-term consequences from over use.”

Antibiotics In Children Can Trigger Allergies And Asthma Later In Life

Antibiotics In Children Can Trigger Allergies And Asthma Later In Life

Conclusion

A new study showed that antibiotics can cause allergies and asthma later in life. The reason seems to be that our gut bacteria react to the antibiotics and the gut dysbiosis (disbalance of the gut bacteria) persists, when the antibiotics have been discontinued. The immune system can then react in ways that are detrimental to the child and adolescent. Anaphylaxis, asthma, atopic dermatitis, allergic rhinitis, allergic conjunctivitis or contact dermatitis are all different manifestations of allergies that can develop later in life. At this point we only know that there is an association between these allergic manifestations and the antibiotic use in childhood. More clinical trials will need to shed a light on what causes allergies in some children, but not in others.